Charges Related To Restructuring Activities - Narrative (Details) - USD ($)	3 Months Ended							12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Charges	$ (377,000)	$ (547,000)	$ (1,552,000)	$ (2,701,000)	$ (1,580,000)	$ (1,685,000)	$ (1,392,000)	$ (2,534,000)	$ (7,358,000)	$ (11,829,000)
Payments								(8,305,000)	(8,132,000)	(6,484,000)
Severance
Restructuring Cost and Reserve [Line Items]
Charges								(1,860,000)	(7,012,000)	(11,562,000)
Payments								(7,627,000)	(7,786,000)	(6,196,000)
Contract Terminations
Restructuring Cost and Reserve [Line Items]
Charges								(674,000)	(346,000)	(267,000)
Payments								(678,000)	(346,000)	(288,000)
North America
Restructuring Cost and Reserve [Line Items]
Charges								(964,000)	(1,306,000)	(1,617,000)
Payments								(661,000)	(1,338,000)	(2,087,000)
North America | Severance
Restructuring Cost and Reserve [Line Items]
Charges								(964,000)	(1,306,000)	(1,573,000)
Payments								(661,000)	(1,338,000)	(2,018,000)
North America | Contract Terminations
Restructuring Cost and Reserve [Line Items]
Charges								0	0	(44,000)
Payments								0	0	(69,000)
Europe
Restructuring Cost and Reserve [Line Items]
Charges								(1,560,000)	(5,934,000)	(9,579,000)
Payments								(7,468,000)	(6,436,000)	(3,350,000)
Europe | Severance
Restructuring Cost and Reserve [Line Items]
Charges								(886,000)	(5,588,000)	(9,356,000)
Payments								(6,790,000)	(6,090,000)	(3,131,000)
Europe | Contract Terminations
Restructuring Cost and Reserve [Line Items]
Charges								(674,000)	(346,000)	(223,000)
Payments								(678,000)	(346,000)	(219,000)
All Other
Restructuring Cost and Reserve [Line Items]
Charges								(10,000)	(118,000)	(633,000)
Payments								(176,000)	(358,000)	(1,047,000)
All Other | Severance
Restructuring Cost and Reserve [Line Items]
Charges								(10,000)	(118,000)	(633,000)
Payments								(176,000)	(358,000)	(1,047,000)
All Other | Contract Terminations
Restructuring Cost and Reserve [Line Items]
Charges								0	0	0
Payments								$ 0	$ 0	$ 0